What’s Vulnerable › Vulnerabilities
CVE-2020-8492
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 6.6% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2020-01-30 · updated 2026-10-14
- Weakness: CWE-400
Description
Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.
Affected products
- Canonical Ubuntu Linux: 12.04, 14.04, 16.04, 18.04, 19.10, 20.04
- Debian Linux: 9.0
- Fedoraproject Fedora: 31, 32
- openSUSE Leap: 15.1
- Python: from 2.7.0 through 2.7.17; from 3.5.0 through 3.5.9; from 3.6.0 through 3.6.10; from 3.7.0 through 3.7.6; from 3.8.0 through 3.8.1
References
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00003.html
- https://bugs.python.org/issue39503
- https://github.com/python/cpython/pull/18284
- https://lists.apache.org/thread.html/rdb31a608dd6758c6093fd645aea3fbf022dd25b37109b6aaea5bc0b5%40%3Ccommits.cassandra.apache.org%3E
- https://lists.apache.org/thread.html/rfec113c733162b39633fd86a2d0f34bf42ac35f711b3ec1835c774da%40%3Ccommits.cassandra.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
- https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7WOKDEXLYW5UQ4S7PA7E37IITOC7C56J/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A5NSAX4SC3V64PGZUPH7PRDLSON34Q5A/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APGWEMYZIY5VHLCSZ3HD67PA5Z2UQFGH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UESGYI5XDAHJBATEZN3MHNDUBDH47AS6/
- https://python-security.readthedocs.io/vuln/urllib-basic-auth-regex.html
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